In conventional high speed punching machines, the cutting end of the punch after a period of use requires sharpening, typically by grinding. Sharpening, however, shortens the punch. To ensure proper positioning after sharpening, the punch must be readjusted. Often conventional punching machines require complete disassembly of their spring assemblies in order to sharpen and adjust the punch. Disassembly of the spring assemblies is time consuming and frequently requires the use of special tools. Moreover, the spring assemblies of conventional punching machines include many parts that require additional labor to assemble.
Examples of conventional punching machines include U.S. Pat. No. 4,440,052 to Weisbeck; U.S. Pat. No. 4,141,264 to Weisbeck; U.S. Pat. No. 4,092,888 to Wilson; U.S. Pat. No. 3,958,476 to Bartha; U.S. Pat. No. 3,741,056 to Saladin; and U.S. Pat. No. 939,958 to Koelsch; the subject matter of each of which is hereby incorporated by reference.